ata5780 ATMEL Corporation, ata5780 Datasheet - Page 12

• Manufacturer Part Number: ata5780
• Description: Uhf Ask/fsk Receiver
• Manufacturer: ATMEL Corporation

4. Block Description
4.1
Figure 4-1.
12
SPDT_ANT
General Circuit Description (System Block (Module))
SPDT_RX
RFIN_HB
RFIN_LB
Atmel ATA5780 [Preliminary]
Simple System Block Diagram
LNA, Mixer
Image Rej.
Damping
SPDT
Figure 4-1
The crystal oscillator and the fractional-N PLL generate the reference signal for the mixer
which down-converts the incoming signal to the IF frequency of approx. 251kHz. The Atmel
ATA5780 covers the worldwide ISM frequency ranges of 315MHz, 434MHz, 868MHz, and
915MHz. Two completely different low noise amplifiers (LNA) were designed for the low- and
high-frequency band. The IF signals are sampled using high resolution ADC. The baseband
signal processing is performed using the digital signal after the ADC. The digital RSSI signal is
measured after the channel filter. Two completely different reception paths A and B can be
set, making the combination of settings more flexible.
XTAL1
Front-End
Fractional
Temp ( )
A
Control
N-PLL
XTO
shows the simple system block diagram of ATA5780.
XTAL2
D
Modulator
Rx DSP
SSI
PB (0 to 7)
SRC, FRC
Oscillators
Watchdog
Port B (8)
Timers
Timers
Timer
16 Bit
8 Bit
IRQ
3x
2x
AVCC
Supplies
DATA BUS
Reset
Clock
Man.
CRC
and
ROM
SPI
VS
NVM Controller
DVCC
AVR CPU
EEPROM
PC (0 to 5)
Port C (6)
Voltage
Monitor
Debug
SRAM
Wire
9207BS–RKE–01/11
®